While you're walking to where your ride will pick you up you can be, for example, checking your email, and your location will update as you move. Of course you

While you're walking to where your ride will pick you up you can be, for example, checking your email, and your location will update as you move. Of course you could stand in a fixed position and keep perfect discipline about staying in the Uber app instead, but that's a very inflexible user experience.